be no different from that of the comparison populations. The incidences and types of diseases affecting all groups were similar, and there was no clear evidence of accelerated aging or cataract formation, of decreased longevity, increased mortality, or increased incidence of malignancy (other than thyroid). B. Methods l. Procedures Extended field trips for general examinations were made at least annually, and more frequently during certain periods, following the accident. For major field surveys, the medical team usually consisted of a dozen technological support personnel and four to six physicians, including an expert thyroidologist, a hematologist and a pediatrician when possible, and sometimes a gynecologist and a dentist. During the past six years, a physician and a technologist in full-time residence in Kwajalein have attempted to make quarterly vists to hold general sick call, to conduct follow-up evaluations of continuing problems, and to promote general health care and education among the populace. Table 1 shows the current locations of various members of the examination group. Many are now congregated at the major population centers: Majuro (the Trust Territory District Center) and Ebeye Island in Kwajalein Atoll. Medical facilties established on these islands by Brookhaven National Laboratory included two large trailers which provided semipermanent quarters for physical, x-ray, and laboratory examinations. Additional support was available from nearby Trust Territory hospitals. The outer islands, including Rongelap and Utirik, necessitated shipborne surveys, since they were essentially inaccessible by air. During the past six years, two chartered vessels were modified to transport the entire medical team and to provide on-board examination facilities and equipment for outer island surveys. These were supplemented by trailers and Butler buildings on some islands. Table 1. Locations of Marshall Islands groups under study, 1979. Group Rongelap + Ailinginae exposed Rongelap unexposed Utirik exposed Utirik unexposed Bikini Wotje Likiep Total R U E M K 18 204 4 226 = 54 264 318 20 360 17 29 4 430 ll 111 #30 169 159 480 1 4 2 29 LW = 149 149 - Other Total 2 1 6 155 164 5 72 10 16 31 134 l = R = Rongelap; U = Utirik; E = Ebeye; M = Majuro; K = Kilis3 L = Likiep; ° = Wotje. 55 753 £112 478 £228 155 149 1930